I think one of the problems about arguing the saturation effect is that that's how the guys using the homophobic slurs see it in their world. To [i]them[/i], everyone does it so it's ok.

I think one of the differences for why gendered slurs feel less threatening is that male hockey players generally aren't members of the group being targeted by the slur, whereas with homophobic slurs, they might be. (Though I would be interested to hear the perspective of trans women who have had to deal with gendered slurs whilst incorrectly presumed to be men.)